Catalytic co-pyrolysis of rice husk and high-density polyethylene using dolomite for enhancement of bio-oil production and quality.

Abstract

This study focuses on producing hydrocarbon-based liquid fuels through a catalytic thermochemical process utilizing high-density polyethylene (HDPE) plastic waste and rice husk biomass (RH), with an emphasis on thermogravimetric analysis and gas chromatography-mass spectrometry (GC-MS). Additionally, efforts were made to investigate the kinetic characteristics of the blends at different conversion rates employing the KAS and OFW methodologies. The analysis revealed that the activation energy of HDPE:RH (1:1, wt%) was measured at 126.4 kJ/mol and 114.9 kJ/mol. The dolomite catalyst was calcined at 900 °C to increase its activity as a catalyst. The used dolomite catalyst was calcined at 900 °C and had a surface area (S_BET) of 7.45 m²/g, with average particle sizes of CaO and MgO of 77.8 nm and 43.7 nm. Results showed the catalytic co-pyrolysis of HDPE and RH enhanced the fuel properties by 15-20% that were performed at 500 °C at 10 °C/min. The aniline point was found to be 55.4 g/cm³, the fire point and the flash point were 52.2 °C and 49.6 °C, respectively, while the cetane number was determined to be 51.3. A 72.4% increase in carbon content, 12.26% increase in hydrogen content, and decrease in the oxygen extracted from the bio-oil by 17% were also observed.